Destructive distillation op resinous wood with superheated steam



R. FRYE May 16, 1933.

DESTRUCTIVE DISTILLATION OF,RESINOUS WfJOD WITH SUPERHEATED STEAM Filed July 28, 1951 Oohdenser lmn lih v v IUenZk: fliw- 1 Patented May 16, 1933 UNITED STATES ROBERT rare, or ALEXANDRIA, LOUISIANA DESTRUGTIVE DISTILLATION OF BESINOUS WOOD WITH SIJ'PERHEA'IED STEAM Application filed July 28,

uct and at the same time effect an economy,

since it is found that a larger amount of material can be treated in a shorter time to give an increased yield, and at the same time prevents the formation of tar coke ordinarily encountered on the retort bottoms, as destructive distillation of resinous wood is usually carried out. This coke is objectionable since it prevents proper heat transfer, is injurious to the retort bottoms, and

necessitates cooling the retorts at intervals to remove same by mechanical means.

In carrying out the invention, I employ retorts of any suitable character and size. Such retorts are preferably rendered airtight and the retort condenser outlets are under a slight vacuum at all times of approximately four inches water pressure.

The resinous wood such as pine wood to be destructively distilled is placed in the retort,

preferably in suitable receptacles or containers and superheated steam is introduced 'to the retort to drive out any contained air.

The retort in which is disposed the resinous material in a suitable container as described is subjected to an external heating until the When the distillation has been completed 1931. Serial R0. 553,699.

the retorts are opened, the substantially tar free charred contents and containers are removed, and a new charge is introduced into the retorts.

It will be understood that in accordance with this process a large amount of resinous material may be destructively distilled and I have found that not only is the time element extremely satisfactory, but the yield is much higher than heretofore obtained.

Also, instead of stopping the process and allowing the retort to cool while removing the containers, the process may be carried (:11 continuously by supplying the resinous material to a travelling belt or containers carried by a travelling belt or conveyor. In fact, any convenient process for continually ponducting the distillation will be satisfacory.

I have found that by initially driving out the air with superheated steam and thereafter heating the retort to a temperature approximating that of the boiling point of water before introducing the superheated steam for distillation purposes, that the process is extremely effective and results in a more complete volatilization than is possible with conventional methods. In other words, by initially heating the retort and contents and thereafter introducing superheated steam while continuing the external heating, the volatilization or destructive distillation is substantially com lete.

The process is c aracterized by subjecting the resinous wood to the direct action of the superheated steam, and, as stated, the external heating is continued and the temperature raised until the desired point of volatilization is reached.

It is clear that the process may be departed from in various changed or modified ways, all of which are considered as comprehended within the appended claim. The drawing is a diagrammatic view of a retort having an external heating means A, and an internal injector means B, for supplying superheated steam to the interior of the retort. C is the outlet from the retort to the condenser D.

I claim:

The process of destructively distilling resinous wood to obtain a wood distillate, which comprises charging the wood into a retort from which the air has been exhaust- 3 ed, preliminarily heating the retort and its contents to a temperature of substantially 212 F., introducing superheated steam at a temperature of 500 to 800 F. to the heated wood in the retort and simultaneously heating the retort externally until the interior of the retort registers a tem rature up to substantially 750 to 950 maintaining this temperature until the volatile resinous constituents have been removed, and a substantially tar free char remains, and condensing such volatiles.

In testimony whereof I aflix my signature.

ROBERT FRYE. 

